A 35-year-old man presents to the emergency department for evaluation of progressive fatigue and pruritus for the past month. His medical history is significant for ulcerative colitis diagnosed 8 years ago, currently treated with mesalamine. Temperature is 36.8°C (98.2°F), blood pressure is 118/72 mm Hg, pulse is 76/min, and respiratory rate is 14/min. Physical examination reveals mild scleral icterus. Laboratory studies demonstrate alkaline phosphatase of 510 U/L, total bilirubin of 2.4 mg/dL, AST of 72 U/L, and ALT of 80 U/L. Magnetic resonance cholangiopancreatography (MRCP) demonstrates multifocal strictures and segmental dilatations of the intrahepatic and extrahepatic bile ducts.
Which of the following is the most likely diagnosis?
The correct answer is:
C: Primary sclerosing cholangitis.
This patient has a cholestatic pattern of liver injury, pruritus, and characteristic biliary strictures on MRCP. The strong association between ulcerative colitis and primary sclerosing cholangitis (PSC) is an important clue. PSC is characterized by chronic inflammation and fibrosis of the bile ducts, leading to multifocal strictures and progressive cholestatic liver disease.
Answer choice A: Autoimmune hepatitis, is incorrect.
Autoimmune hepatitis may cause elevated liver enzymes and fatigue. However, it typically produces a hepatocellular rather than cholestatic pattern of liver injury and is not associated with the characteristic biliary abnormalities seen on MRCP.
Answer choice B: Primary biliary cholangitis, is incorrect.
Primary biliary cholangitis (PBC) can also present with pruritus and elevated alkaline phosphatase levels. However, it primarily affects middle-aged women and involves autoimmune destruction of small intrahepatic bile ducts. PSC is more strongly associated with ulcerative colitis and produces the characteristic beading appearance on cholangiography.
Answer choice D: Secondary hemochromatosis, is incorrect.
Hemochromatosis can cause chronic liver disease but does not produce multifocal biliary strictures or cholestatic laboratory abnormalities.
Answer choice E: Wilson disease, is incorrect.
Wilson disease typically presents at a younger age with hepatic, neurologic, or psychiatric manifestations and does not cause the cholangiographic findings seen here.
Key Learning Point
Primary sclerosing cholangitis is strongly associated with ulcerative colitis and causes multifocal biliary strictures resulting in cholestatic liver disease.
